Gas burner

ABSTRACT

A gas burner includes a looped head seat formed by punching a metal plate, and defining therein a surrounding duct therein which is fluidly communicated with a gas conduit for supplying fuel gas to the surrounding duct, and a looped burner cap engaged with the head seat to define a partition space therebetween. One of inner and outer surrounding regions of an upper wall of the head seat has a plurality of intercommunicating ports, whereas one of corresponding inner and outer surrounding regions of an upper cap wall of the burner cap has a plurality of discharging orifices such that the fuel gas in the surrounding duct is guided to flow through the intercommunicating ports into the partition space and is discharged through the discharging orifices. By means of the arrangement of the ports and the orifices, occurrence of backfires in the surrounding duct can be prevented.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a gas burner, more particularly to a gas burner which can prevent occurrence of a backfire therein.

2. Description of the Related Art

Referring to FIG. 1, a conventional gas burner is shown to include a head body 1 and a gas conduit 2 extending outwardly from and integrally formed with the head body 1 by casting. The head body 1 has a plurality of orifices 101 for ejection of flames. The conventional gas burner is disadvantageous in that when a gas valve (not shown) is closed to stop a supply of fuel gas to the head body 1, since some fuel gas remains in the gas burner and since ambient air rapidly enters the gas burner, a backfire often occurs in the gas burner and results in a loud detonation. Moreover, in manufacturing the conventional gas burner by casting, a resin material is used as a sand core, and the resin material is melted and removed when a liquid metal is poured into a mold. Such a manufacturing process is relatively complicated and is not environmentally friendly.

Referring to FIG. 2, another conventional gas burner is shown to include a head seat 3, an outer surrounding piece 4 secured on the head seat 3, an inner surrounding piece 5 disposed inwardly of the outer surrounding piece 4 and secured on the head seat 3, and a looped burner cap 6 mounted on the outer and inner surrounding pieces 4, 5. The head seat 3 includes top and bottom shells 302, 301 which are formed by punching a single piece of metal so as to be manufactured in an environmental-friendly manner and at a relatively low cost. However, the problem of backfiring still exists.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a gas burner which is manufactured at a relatively low cost and in an environmental-friendly manner, and which can prevent occurrence of a backfire therein.

According to this invention, the gas burner includes a looped head seat and a looped burner cap. The head seat has a looped bottom wall surrounding a central axis, outer and inner surrounding walls extending respectively in an upright direction from outer and inner peripheries of the bottom wall to terminate at outer and inner edges, respectively, and a looped upper wall interconnecting the outer and inner edges. The bottom wall, the outer and inner surrounding walls, and the upper wall define a surrounding duct thereamong. The upper wall has inner and outer first surrounding regions perimetrically opposite to each other and surrounding the central axis. The burner cap has inner and outer cap peripheries that are perimetrically opposite to each other, that surround the central axis, and that are engaged with the inner and outer edges, respectively, to define a partition space between the burner cap and the upper wall. The burner cap further has an upper cap wall that extends to surround the central axis, and that is interposed between the inner and outer cap peripheries. The upper cap wall has inner and outer second surrounding regions that correspond to and that are spaced apart from the inner and outer first surrounding region, respectively, in the upright direction by the partition space. A gas conduit is disposed upstream of the surrounding duct, and is adapted for passage fuel gas to the surrounding duct. The upper wall of the head seat has a plurality of intercommunicating ports angularly displaced from one another about the central axis. The upper cap wall has a plurality of discharging orifices angularly displaced from one another about the central axis such that the fuel gas in the surrounding duct is guided to flow through the intercommunicating ports into the partition space, and is discharged through the discharging orifices. The discharging orifices are located in one of the inner and outer second surrounding regions, whereas the intercommunicating ports are located in one of the inner and outer first surrounding regions which corresponds to the other one of the inner and outer second surrounding regions. By means of the arrangement of the intercommunicating ports and the discharging orifices, occurrence of backfires in the surrounding duct can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments of the invention, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a conventional gas burner;

FIG. 2 is a sectional view of another conventional gas burner;

FIG. 3 is a sectional view of the first preferred embodiment of a gas burner according to this invention;

FIG. 4 is a top view of the first preferred embodiment;

FIG. 5 is a sectional view of the second preferred embodiment of a gas burner according to this invention;

FIG. 6 is a top view of the second preferred embodiment;

FIG. 7 is a sectional view of the third preferred embodiment of a gas burner according to this invention; and

FIG. 8 is a top view of the third preferred embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before the present invention is described in greater detail, it should be noted that same reference numerals have been used to denote like elements throughout the specification.

Referring to FIGS. 3 and 4, the first preferred embodiment of a gas burner according to the present invention is shown to comprise a head unit 10 and a looped burner cap 20. The head unit 10 includes a lower shell piece 11 formed by punching a metal plate, and an upper shell piece 12 formed by punching a metal plate and secured on the lower shell piece 11 by a rolling process so as to cooperatively form a looped head seat 13 and a gas conduit 14 extending laterally and outwardly from the head seat 13.

The head seat 13 has a looped bottom wall 134 with inner and outer peripheries perimetrically opposite to each other and surrounding a central axis, an outer surrounding wall 136 extending in an upright direction from the outer periphery of the bottom wall 134 to terminate at an outer edge, an inner surrounding wall 135 extending from the inner periphery of the bottom wall 134 in the upright direction to terminate at an inner edge that is perimetrically opposite to the outer edge, and a looped upper wall 133 interconnecting the outer and inner edges. The bottom wall 134, the outer and inner surrounding walls 136, 135, and the upper wall 133 define a surrounding duct 131 thereamong. The upper wall 133 has inner and outer first surrounding regions 137, 138 perimetrically opposite to each other and surrounding the central axis, and a first inside surrounding region 132 interconnecting the inner first surrounding region 137 and the inner edge of the inner surrounding wall 135. The outer first surrounding region 138 and the first inside surrounding region 132 are inclined downwardly from the inner first surrounding region 137 to the respective outer and inner edges such that the upper wall 133 has a U-shaped cross-section, and are formed with shoulders 139 adjacent to the respective outer and inner edges. The upper wall 133 has a plurality of intercommunicating ports 130 which are angularly displaced from one another about the central axis. The intercommunicating ports 130 may be a plurality of circular holes. The gas conduit 14 is disposed upstream of the surrounding duct 131, and is adapted for passage of fuel gas to the surrounding duct 131.

The burner cap 20 is formed by punching a single piece of metal, and has inner and outer cap peripheries 23, 24 which are perimetrically opposite to each other, which surround the central axis, and which are engaged with the inner and outer edges, respectively, to define a partition space 30 between the burner cap 20 and the upper wall 133. The burner cap 20 further has an upper cap wall 21 which extends to surround the central axis, and which is interposed between the inner and outer cap peripheries 23, 24. The upper cap wall 21 has inner and outer second surrounding regions 217, 218 which are perimetrically opposite to each other, which surround the central axis, and which correspond to and which are spaced apart from the inner and outer first surrounding regions 137, 138, respectively, in the upright direction by the partition space 30, and a second inside surrounding region 212 which interconnects the inner second surrounding region 217 and the inner cap periphery 23 and which corresponds to and which is spaced apart from the first inside surrounding region 132 in the upright direction by the partition space 30. The outer second surrounding region 218 and the second inside surrounding region 212 are inclined downwardly from the inner second surrounding region 217 to the respective outer and inner cap peripheries 24, 23 such that the upper cap wall 21 has a U-shaped cross-section. Each of the outer second surrounding region 218 and the second inside surrounding region 212 has a plurality of discharging orifices 221 which are angularly displaced from one another about the central axis. The discharging orifices 221 may include circular and elongated holes 223, 222. Thus, the fuel gas which flows in the surrounding duct 131 is guided to flow through the intercommunicating ports 130 into the partition space 30 for ejection through the discharging orifices 221.

As illustrated, the discharging orifices 221 are arranged not to align with the intercommunicating ports 130. Hence, when a gas valve (not shown) of the gas burner according to this embodiment is closed to stop the supply of fuel gas to the surrounding duct 131, the ambient air rapidly entering the gas burner through the discharging orifices 221 is blocked by the outer first surrounding region 138 and the first inside surrounding region 132 such that the air flow is slowed down and such that any resultant combustion occurs in the partition space 30. Thus, occurrence of backfires in the surrounding duct 131 can be prevented.

Furthermore, since the head unit 10 and the burner cap 20 are formed from a metal plate by punching, manufacture thereof is easy and less costly, and can be conducted in an environmental-friendly manner.

Referring to FIGS. 5 and 6, the second preferred embodiment of a gas burner according to this invention is shown to be similar to that of the previous embodiment in construction and function. In this embodiment, the head unit 10 of the gas burner further includes a central head seat 13′ which is surrounded by and which is integrally formed with the head seat 13 and which defines a central duct 131′ therein. The central head seat 13′ has a central upper wall 133′ which has a first central region 137′ that is formed with a plurality of central intercommunicating ports 130′. A passage 120 communicates the surrounding duct 131 with the central duct 131′ so as to be adapted for passage of the fuel gas to the central duct 131′. The gas burner of this embodiment further comprises a central burner cap 20′ which has an upper central cap wall 21′ engaged with the central head seat 13′ to define a central partition space 30′ therebetween. The upper central cap wall 21′ has a second central region 211′ that corresponds to the first central region 137′ in the upright direction, and a surrounding region 212′ that is perimetrically opposite to the second central region 211′, that surrounds the central axis, and that has a plurality of central discharging orifices 221′ such that the fuel gas in the central partition space 30′ is discharged through of the central discharging orifices 221′.

Referring to FIGS. 7 and 8, the third preferred embodiment of a gas burner according to this invention is shown to be similar to that of the aforesaid second embodiment in construction and function. In this embodiment, the head unit 10 of the gas burner defines a central duct 131′ and a surrounding duct 131 which are fluidly communicated with two different gas conduits 14, 15, respectively. Hence, the passage 120 of the aforesaid second preferred embodiment can be omitted.

While the present invention has been described in connection with what is considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretations and equivalent arrangements. 

1. A gas burner comprising: a looped head seat having a looped bottom wall with inner and outer peripheries perimetrically opposite to each other and surrounding a central axis, an outer surrounding wall extending in an upright direction from said outer periphery of said bottom wall to terminate at an outer edge, an inner surrounding wall extending from said inner periphery of said bottom wall in the upright direction to terminate at an inner edge that is perimetrically opposite to said outer edge, and a looped upper wall interconnecting said outer and inner edges, said bottom wall, said outer and inner surrounding walls and said upper wall defining a surrounding duct thereamong, said upper wall having inner and outer first surrounding regions perimetrically opposite to each other and surrounding the central axis; a looped burner cap having inner and outer cap peripheries that are perimetrically opposite to each other, that surround the central axis, and that are engaged with said inner and outer edges, respectively, to define a partition space between said burner cap and said upper wall, said burner cap having an upper cap wall that extends to surround the central axis, and that is interposed between said inner and outer cap peripheries, said upper cap wall having inner and outer second surrounding regions that are perimetrically opposite to each other, that surround the central axis, and that correspond to and that are spaced apart from said inner and outer first surrounding regions, respectively, in the upright direction by said partition space; and a gas conduit disposed upstream of said surrounding duct, and adapted for passage of fuel gas to said surrounding duct; said looped upper wall having a plurality of intercommunicating ports which are angularly displaced from one another about the central axis, said upper cap wall having a plurality of discharging orifices which are angularly displaced from one another about the central axis such that the fuel gas in said surrounding duct is guided to flow through said intercommunicating ports into said partition space and is discharged through said discharging orifices, said discharging orifices being located in one of said inner and outer second surrounding regions, said intercommunicating ports being located in one of said inner and outer first surrounding regions which corresponds to the other one of said inner and outer second surrounding regions.
 2. The gas burner of claim 1, wherein said discharging orifices are located in said outer second surrounding region, and said intercommunicating ports are located in said inner first surrounding region.
 3. The gas burner of claim 2, wherein said looped upper wall further has a first inside surrounding region interconnecting said inner first surrounding region and said inner edge, said upper cap wall further having a second inside surrounding region which interconnects said inner second surrounding region and said inner cap periphery and which corresponds to and which is spaced apart from said first inside surrounding region in the upright direction by said partition space, said second inside surrounding region having a plurality of inside discharging orifices which are angularly displaced from one another about the central axis.
 4. The gas burner of claim 3, wherein each of said outer first surrounding region and said first inside surrounding region is inclined downwardly from said inner first surrounding region to a respective one of said outer and inner edges, and each of said outer second surrounding region and said second inside surrounding region is inclined downwardly from said inner second surrounding region to a respective one of said outer and inner cap peripheries.
 5. The gas burner of claim 4, wherein said burner cap is formed by punching a single-piece of metal.
 6. The gas burner of claim 1, wherein each of said looped bottom wall and said looped upper wall of said head seat is formed by punching a single piece of metal.
 7. The gas burner of claim 1, further comprising: a central head seat which is surrounded by and which is integrally formed with said looped head seat and which defines a central duct therein, said central head seat having a central upper wall which has a first central region that is formed with a plurality of central intercommunicating ports to be communicated with said central duct; a passage communicating said surrounding duct with said central duct so as to be adapted for passage of fuel gas to said central duct; and a central burner cap having an upper central cap wall which is engaged with said central head seat to define a central partition space therebetween, and which has a second central region that corresponds to said first central region in the upright direction, and a surrounding region that is perimetrically opposite to said second central region, that surrounds the central axis, and that has a plurality of central discharging orifices such that the fuel gas introduced through said central intercommunicating ports into said central partition space is discharged through said central discharging orifices. 